Refractory-lined container for scrap

ABSTRACT

A scrap container wherein scrap is preheated, having the inner surface of the shell lined with refractory material, including a first expansion means atop the refractory lining and a second expansion means below the refractory lining.

United States Patent Reinhold et al.

[ Nov. 13, 1973 REFRACTORY-LINED CONTAINER FOR SCRAP Inventors: RichardJ. Reinhold, Allentown;

Melvin J. Mateer, Middletown; John F. Muhlhauser, Lemoyne,

all of Pa. Assignee: Bethlehem Steel Corp., Bethlehem,

Filed: July 3, 1972 Appl. No.1 263,414

U.S. Cl. 266/5 n, 266/24 Int. Cl. F2'7b 17/00 Field of Search 266/5 R, 5F, 24,

[56] References Cited UNITED STATES PATENTS 2,804,295 8/l957 Brooke266/5 R Primary Examiner-Gerald A. Dost Attorney-Joseph J. OKeefe [57]ABSTRACT A scrap container wherein scrap is preheated, having the innersurface of the shell lined with refractory material, including a firstexpansion means atop the refractory lining and a second expansion meansbelow the refractory lining.

12 Claims, 2 Drawing Figures REFRACTORY-LINED CONTAINER FOR SCRAPBACKGROUND OF THE INVENTION This invention is directed to an improvedcontainer in which scrap is preheated prior to charging into an electricarc furnace. The container is lined with refractory shapes. Steelmakingprocesses, for example, openhearth, basic oxygen, electric-arc and thelike, use cold steel and/or iron scrap as at least a portion of the rawmaterial chargeplaced in the steelmaking furnaces. About 35 percent toabout 60 percent of the raw material charge in the open-hearth processis scrap. The basic oxygen process uses about 25 percent to 30 percentscrap in the raw material charge. The electric-arc process usessubstantially 100 percent scrap. Scrap is included in the raw materialcharge because it is readily available and is generally cheaper than hotmetal. Then, too, some plants may not have a sufficient source of hotmetal to make up the required raw material charge. The use of scrap alsoconserves the available iron ores and concentrates for future use.

Prior practices have been to charge cold scrap into the furnace used toproduce steel. As a result, heating time was increased because the scraphad to be heated to melting temperature before refining took place inthe steelmaking process. Previous attempts to preheat the scrap prior tocharging into a steelmaking furnace have been made. The scrap has insuch vcases been charged into a refractory-lined container wherein hotcombustion gases are passed toward or downwardly through the scrap.

One such container and attendant apparatus used to preheat scrap isshown in application Ser. No. 238,870, filed Mar. 28, 1972, in the nameof R. J. Reinbold et al. and titled Apparatus and Method for PreheatingScrap.

The refractory lining in the described container is supported by asteelrefractory support ring welded to the inside surface of the cylindricalshell of the container at or near the bottomthereof. The refractorylining extends upwardly to the top of the-container. When hot combustiongases, such as are formed by burning natural gas in a refractory-linedburner hood resting atop the container, are passed through the scrapcharge to heat the scrap, the refractory lining is heated and expands.The refractory lining cannot expand downwardly because of the refractorysupport ring welded to the shell of the furnace. Therefore, therefractory lining will expand upwardly. However, because of the weightof the hood atop the container, the expansion of the refractory lininginan upwardly direction is retarded. The refractory lining, however,must expand in some direction as it is heated and thus expands upwardlyas much as it can, and then buckles inwardly into the container, formingbulges in the refractory lining of the container.

When a load of scrap is charged into the container, the scrap bumps thetopmost refractory causing it to break and fall out of the-lining intothe container. The impact of the scrap on the refractory lining can alsobreak the refractory lining at the bulges in the lining. Furthermore,when the burner hood is removed from atop the container, the refractorylining being hot, expands upwardly beyond the top of the container. Whenthe burner hood is then lowered atop the container to preheat the nextscrap charge, the refractory lining which extends above the container isbroken. In addition, when the refractory lining contracts duringcooling, the lining tends to pull away from the shell. In any of thesecases, frequent repair of the refractory lining is usually necessary,thereby increasing the cost of operation and causing delay in meltingand refining steel because of reduced availability of the containers.

Another problem arises because scrap charged into the container cancontain elongated pieces, for example, rails, structural shapes and thelike. Elongated pieces of scrap charged into the bottom of the containercan frequently extend all the way from the base of the clam to the wallof the container beneath the refractory support ring. The elongatedpieces of scrap be come wedged between the underside of the refractorysupport ring and the clam. The wedged pieces of scrap make it extremelydifficult, if not impossible, to open the clam when it is desired tocharge the scrap into an electric furnace. If the clam opening apparatusis forced, the cables by which the clam is opened can fail making itimpossible to open the clam. The container must then be placed on thefloor of the shop and the scrap charge cooled to temperaturesufficiently low so that the scrap charge can be removedby the use ofelectromagnets.

Forcibly opening the clam will sometimes dislodge the wedged pieces ofscrap; however, in this event the refractory lining in the adjacentareas can be damaged or the clam itself can be damaged. In any event,the additional steps involved in getting wedged scrap out of thecontainer, for example, time consumed in cooling the scrap charge,removing the scrap charge from the container by the use ofelectromagnets, and removing the container from service for repair, areadditional costs which must then be added to production costs. Inaddition, production lags-because of the time element involved in repairof the container and because of the reduced availability of thecontainer during the time required for cable replacement and the like.

It is therefore an object of this invention to provide SUMMARY OF THEINVENTION Broadly, the apparatus of the invention is a container havingthe interior lined with refractory materials, a first expansion'meansassociated with the top of the refractory lining and a second expansionmeans associated with the bottom of the refractory lining.

DESCRIPTION. OF THE DRAWINGS FIG. 1 isa view in cross-section of theimproved container of the invention.

FIG. 2 is an enlarged view of the circled area 2 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings of theinvention, FIG. 1 is a cross-sectional view of a portable container 16for use in preheating scrap. The portable container 16 is a vertical,generally cylindrical steel shell 17 having a normally open upper end 18through which scrap can be charged therein, and a normally closed lowerend 19. The closure on the lower end comprises a clam which has twoidentical partible swinging jaws 23 and 24.

Each of the partible jaws 23 and 24 has a bracket 26 and 27 respectivelyat the periphery of the jaw; each of which brackets is provided with anopening 28 and 29 respectively. One end of cables 28a and 29a isrespectively fixedly attached to the partible jaws 23 and 24 through theopenings 28 and 29. The other end of each of: the cables 28a and 29a isfastened to appropriate equipment (not shown) which when supported by anoverhead crane and attendant crane hooks (also not shown) is used toopen the partible jaws 23 and 24 by pulling the cables 28a and 29a. Eachof the partible jaws 23 and 24 is provided with a semi-cylindrical steelsupport member 30 and 31 fastened, for example, by welding, to thebottom thereof.

Container 16 is provided with lifting means comprising a pair of opposedtrunnions 32 and 33 and attendant structural steel supports 34 and 35whereby the container 16 can be lifted, for example, by a crane, andcarried to a steel-making furnace for discharge of preheated scrap intothe furnace.

A refractory lining shown generally at 36 is laid-up against the insidesurface of the shell 17 of the container 16. The refractory lining 36,which is made up of refractory shapes laid-up in parallel horizontalrows 42, is supported by a refractory support steel ring 37 welded tothe inside surface of shell 17 in the lower portion thereof. Steelbrackets or gussets 37b are welded to the inside of the shell 17 beneaththe refractory support ring 37 to help in the support thereof. Thebrackets 37b are spaced around the periphery of the inside of the shell17. The refractory lining 36 extends upwardly from the refractorysupport ring 37 toward the top of the container but terminates adistance therefrom. The distance from the top of the refractory lining36 in the shell 17 to the top of the shell of the container is equal toabout the length of one of the re fractory shapes used to line the shell17' of the container 16. A burner hood support steel ring 38 having agenerally inverted U-shape is attached to the top of the shell 17 toprovide a substantially flat surface 39 whereon a burner hood (notshown) can be supported. The legs 38:; and 38b extend downwardly overthe shell 17 to aid in positioning the ring 38.

A plurality of steel anchor members 40 equally spaced from each otherand extending 360 around the inside periphery of the steel shell 17 arefixedly attached to the shell in the top portion thereof between the topof the refractory lining 36 and the top of the container 16. Arefractory material 41 capable of withstanding elevated temperatures isrammed into place between the top row 42 of the refractory lining 36 andthe steel ring 38 attached to the top of the container 16. The rammedrefractory material is supported in place by the anchor members 40. Whenhot combustion gases pass downwardly through the scrap in the container16, the rammed refractory 41 has enough elasticity at elevatedtemperatures to allow the upward expansion of the refractory lining 36.As a result, the refractory lining does not bulge or buckle but remainsagainst the shell of the container. I

When the scrap is charged into the furnace and the refractory liningcontracts due to cooling, the rammed refractory remains keyed in placeby the anchor members 40. A void is then created between the top courseof the refractory lining and the rammed refractory.

When the refractory lining is again heated by hot combustion gasespassing downwardly through the scrap during the next preheatingoperation, the expansion of the refractory lining fills the void andalso remains in place along the shell of the container. Since therefractory lining does not bulge into the container, the refractorylining is not susceptible to fracture by impact of scrap thereon.

A baffle plate, which can be a steel ring, 43 is attached, for example,by welding, to the bottom of the refractory support steel ring 37 ininclined relationship thereto. The baffle plate 43 extends divergentlydownwardly from the inside portion 37a of the refractory support steelring 37 toward the bottom of the container l6 and terminates a distancefrom the inside surface of the steel shell 17 leaving a gap 44therebetween and forming an enclosure 46 between the shell 17 and ring43. A second baffle plate or baffle 45, which can also be a steel ring,is attached, for example, by welding, to the inside surface of the steelshell 17 and extends convergently upwardly therefrom. The baffle plate43 and the baffle plate 45 overlap and are positioned in close proximityto each other. The two plates are preferably in slidable contact witheach other. In order to protect the shell of the container during thepassage of hot combustion gases downwardly through the scrap, arefractory is rammed into the enclosure 46 between steel rings 43 and45, the shell 17 and the bottom of the support ring 37.

As shown in FIG. 2, which is an enlarged section 2 of FIG. 1, a righttriangularly shaped space or enclosure 46 extending around the peripheryof the container 16 is formed beneath the refractory support steel ring37. A boundary 47 of the space 46 is formed by a portion of the shell17. A second boundary 48 is formed by the refractory support steel ring37. The hypotenuse 50 of the right triangle is formed by the first steelring or baffie 43 and the second steel ring or baffle 45 shownoverlapped and in slidable contact with each other. The space 46 isfilled with a castable refractory 55. When the scrap charge inthecontainer 16 is heated the steel rings 37, 43 and 45 will expand.Because the baffles 43 and 45 are free to expand when heated to elevatedtem peratures, the danger of weld failure due to expansion -is reducedto a minimum. The presence of the baffles 43 and 45 prevents long piecesof scrap from becoming wedged between the clam and the underside ofrefractory support ring 37 and allows the partible jaws 23 and 24'of theclam to be opened without danger of sticking or binding. Failure ofcables 28a and 29a (FIG. 1) is thus minimized. Since there is no unduedisturbance of the refractory lining 36, because of jammed clam jaws,repairs and reliningof the refractory are decreased to a minimum. It ispossible to provide only one of the baf- .fle plates 43 and 45 ininclined relationship to the refractory support ring 37 and the shell 17of the container 16 to prevent elongated pieces of scrap from becomingwedged beneath the refractory support ring 37. If only one of eitherbaffle plate 43 or 45 is used, it must be understood that the singlebaffle plate will not extend the entire distance between the refractorysupport ring 37 and the shell 17 of the container 16 but will terminatea short distance therefrom leaving a gap such as is shown at 44 betweenbaffle plate 43 and the shell 17. The opening or gap between the singlebaffle plate and the adjacent portions of the container will allow forexpansion and contraction of the baffle plate without causing damage tothe refractory of the container. While a single baffle plate can beused, it is much preferred to use the overlapping baffle platearrangement illustrated in FIGS. 1 and 2. I

We claim:

l. A container for preheating scrap in a preheater station, whichcontainer comprises in combination a metallic shell, a refractorysupport ring fixedly attached to and extending around the periphery ofthe inside of the shell in the lower portion thereof, a refractorylining comprised of abutting refractory shapes laid-up against theinside of the shell and extending upwardly therein from the refractorysupport ring toward the top of the shell but in spaced relationshiptherefrom, said space between the refractory shapes and the top of theshell being equal to about one refractory shape length, a pair ofpartible jaws attached to a bracket on the outside of the shell andforming a closure on the bottom of the container, a plurality of anchormembers securely fastened to and spaced 360 around the inside of the topof the container in the space between the top row of the refractorylining and the top of the shell and a compressible rammed refractorylaid-up against the shell of the container in said space between the toplayer of the refractory lining and the top ofthe shell of the containerin alignment with the refractory lining and encasing said anchor memberswhereby said rammed refractory is anchored in place.

2. A container for preheating scrapin a preheater station, whichcontainer comprises in combination a metallic shell, a refractorysupport ring fixedly attached to and extending around the periphery ofthe inside of the shell in the lower portion thereof, a refractorylining laid-up against the inside of the shell and extending upwardlytherein from the refractory support ring to near the top of the shell, apair of partible jaws attached to a bracket on the outside of the shelland forming a closure on the bottom of the container, theimprovement'comprising' a steel baffle plate extending peripherallyaround'the inside of said container and positioned at an inclinationbetween the refractory support ring and the shell of the container andfixedly positioned in the container with a gap between one end of thebaffle plate'an'd adjoining structures of the container. 1

3. The container for preheating scrap according to claim 2 wherein thesteel baffle plate is attached to and downwardly divergent from therefractory support ring toward the inside surface of the shell of thecontainer and terminating a distance therefrom.

4. The container for preheating scrap according to claim 2 wherein thesteel baffle plate is attached to and upwardly divergent from the shellof the container toward the inner edge of the refractory support ringand terminating a distancetherefrom.

5. A container for preheating scrap in a preheater station, whichcontainer comprises in combination a metallic shell, a refractorysupport ring fixedly attached to and extending around the periphery ofthe inside of the shell in the lower portion thereof, a refractorylining laid-up against the inside of the shell and extending upwardlytherein from the refractory support ring to near the top of the shell, apair of partible jaws attached to a bracket on the outside of the shelland forming a closure on the bottom of the container, the improvementcomprising a first steel baffle plate attached to and downwardlydivergent from the refractory support ring toward the inside surface ofthe shell of the container and terminating a distance therefrom and asecond steel baffle plate attached to the inside of the shell of thecontainer in the lower portion thereof and extending upwardly therefromat an angle to the shell toward the refractory support ring andterminating a distance therefrom. 4

6. The container of claim 5 wherein the first and second steel baffleplates overlap.

7. The container of claim 6 wherein the overlapping portions of thefirst and second baffle plates are slidably engaged with each other.

8. A container for preheating scrap in a preheater station, whichcontainer includes a shell, a refractory lining laid-up against theinside of said shell, said refractory lining being supported upon arefractory support steel ring in the lower portion of the container,said refractory lining extending upwardly toward but in spaced relationwith the top of the container and a pair of partible jaws to close thelower end of the container, the improvement comprising:

a. a first expansion means between the top of the containerand the topof the refractory lining therein,

and

b. a second expansion means between the bottom of the refractory supportsteel ring and the bottom of the container.

9. The container of claim 8 in which the first expansion means ofsubparagraph (a) comprises a plurality of anchor means securely fastenedto and spaced 360 around the inside of the shell of the container inspaced relation with the top layer of the refractory lining and the topof the shell of the container, a rammed refractory laid-up against theshell of the container in the space between the top of the refractorylining and the top of the shell of the container in alignment with therefractory lining and encasing said anchor means whereby said rammedrefractory'is anchored in place;

10. The container of claim 8 in which thesecond expansion means ofsubparagraph (b) comprises a first baffle plate attached to anddownwardly divergent from a refractory support steel ring toward thecontainer shell, asecond baffle plate attached to and extendingupwardlyat an angle from'the inner surface of the container shell'towardthe steel refractory support ring and closely adjacent to the firstbaffle plate, said combination of baffle plates forming a hypotenuse ofa right triangle, said right triangle having one leg formed by a portionof the refractory support steel ring and the other leg being formed by aportion of the shell of the container between the bottom thereof and therefractory support steel ring and forming therebetween a righttriangular space.

11. The container of claim 10 wherein the first and second-baffle platesare in slidable contact, and the .right triangular space between theshell and the baffle platesis filledwith a castable refractory.

12; Container of claim 9 in which the second expansion means ofsubparagraph (b) comprises a baffle plate attached to and downwardlydiverging from a refractory support steel ring toward the shell of thecontainer, abaffle plate attached to and extending upwardly at an anglefrom the-inner surface of the shell of the container toward the steelrefractory support ring and in slidable contact with the other baffleplate, said combination of baffle plates forming a hypotenuse of a righttriangle, said right triangle having one boundthereof and the refractorysupport steel ring, the right ary formed by a portion of the reffactorysupport steel triangular space thus formed being filled with a castaringand the other boundary being formed by a portion ble refractory.

of the shell of the container between the bottom

1. A container for preheating scrap in a preheater station, whichcontainer comprises in combination a metallic shell, a refractorysupport ring fixedly attached to and extending around the periphery ofthe inside of the shell in the lower portion thereof, a refractorylining comprised of abutting refractory shapes laid-up against theinside of the shell and extending upwardly therein from the refractorysupport ring toward the top of the shell but in spaced relationshiptherefrom, said space between the refractory shapes and the top of theshell being equal to about one refractory shape length, a pair ofpartible jaws attached to a bracket on the outside of the shell andforming a closure on the bottom of the container, a plurality of anchormembers securely fastened to and spaced 360* around the inside of thetop of the container in the space between the top row of the refractorylining and the top of the shell and a compressible rammed refractorylaid-up against the shell of the container in said space between the toplayer of the refractory lining and the top of the shell of the containerin alignment with the refraCtory lining and encasing said anchor memberswhereby said rammed refractory is anchored in place.
 2. A container forpreheating scrap in a preheater station, which container comprises incombination a metallic shell, a refractory support ring fixedly attachedto and extending around the periphery of the inside of the shell in thelower portion thereof, a refractory lining laid-up against the inside ofthe shell and extending upwardly therein from the refractory supportring to near the top of the shell, a pair of partible jaws attached to abracket on the outside of the shell and forming a closure on the bottomof the container, the improvement comprising a steel baffle plateextending peripherally around the inside of said container andpositioned at an inclination between the refractory support ring and theshell of the container and fixedly positioned in the container with agap between one end of the baffle plate and adjoining structures of thecontainer.
 3. The container for preheating scrap according to claim 2wherein the steel baffle plate is attached to and downwardly divergentfrom the refractory support ring toward the inside surface of the shellof the container and terminating a distance therefrom.
 4. The containerfor preheating scrap according to claim 2 wherein the steel baffle plateis attached to and upwardly divergent from the shell of the containertoward the inner edge of the refractory support ring and terminating adistance therefrom.
 5. A container for preheating scrap in a preheaterstation, which container comprises in combination a metallic shell, arefractory support ring fixedly attached to and extending around theperiphery of the inside of the shell in the lower portion thereof, arefractory lining laid-up against the inside of the shell and extendingupwardly therein from the refractory support ring to near the top of theshell, a pair of partible jaws attached to a bracket on the outside ofthe shell and forming a closure on the bottom of the container, theimprovement comprising a first steel baffle plate attached to anddownwardly divergent from the refractory support ring toward the insidesurface of the shell of the container and terminating a distancetherefrom and a second steel baffle plate attached to the inside of theshell of the container in the lower portion thereof and extendingupwardly therefrom at an angle to the shell toward the refractorysupport ring and terminating a distance therefrom.
 6. The container ofclaim 5 wherein the first and second steel baffle plates overlap.
 7. Thecontainer of claim 6 wherein the overlapping portions of the first andsecond baffle plates are slidably engaged with each other.
 8. Acontainer for preheating scrap in a preheater station, which containerincludes a shell, a refractory lining laid-up against the inside of saidshell, said refractory lining being supported upon a refractory supportsteel ring in the lower portion of the container, said refractory liningextending upwardly toward but in spaced relation with the top of thecontainer and a pair of partible jaws to close the lower end of thecontainer, the improvement comprising: a. a first expansion meansbetween the top of the container and the top of the refractory liningtherein, and b. a second expansion means between the bottom of therefractory support steel ring and the bottom of the container.
 9. Thecontainer of claim 8 in which the first expansion means of subparagraph(a) comprises a plurality of anchor means securely fastened to andspaced 360* around the inside of the shell of the container in spacedrelation with the top layer of the refractory lining and the top of theshell of the container, a rammed refractory laid-up against the shell ofthe container in the space between the top of the refractory lining andthe top of the shell of the container in alignment with the refractorylining and encasing said anchor means whereby said rammed refractory isanchored in place.
 10. The container of claim 8 in which the secondexpansion means of subparagraph (b) comprises a first baffle plateattached to and downwardly divergent from a refractory support steelring toward the container shell, a second baffle plate attached to andextending upwardly at an angle from the inner surface of the containershell toward the steel refractory support ring and closely adjacent tothe first baffle plate, said combination of baffle plates forming ahypotenuse of a right triangle, said right triangle having one legformed by a portion of the refractory support steel ring and the otherleg being formed by a portion of the shell of the container between thebottom thereof and the refractory support steel ring and formingtherebetween a right triangular space.
 11. The container of claim 10wherein the first and second baffle plates are in slidable contact, andthe right triangular space between the shell and the baffle plates isfilled with a castable refractory.
 12. Container of claim 9 in which thesecond expansion means of subparagraph (b) comprises a baffle plateattached to and downwardly diverging from a refractory support steelring toward the shell of the container, a baffle plate attached to andextending upwardly at an angle from the inner surface of the shell ofthe container toward the steel refractory support ring and in slidablecontact with the other baffle plate, said combination of baffle platesforming a hypotenuse of a right triangle, said right triangle having oneboundary formed by a portion of the refractory support steel ring andthe other boundary being formed by a portion of the shell of thecontainer between the bottom thereof and the refractory support steelring, the right triangular space thus formed being filled with acastable refractory.